Not only was the month of July unrivaled for its hot temperatures across the nation, but so too were the first seven months of the calendar year and the last 12 months. In fact, the last four 12-month periods have each successively established new records for the warmest period of that length.

Warmest 12-month periods on record. The last four 12-month periods rank as the #1, #2, #3, and #4 warmest. View big. (NOAA)

During July, some of the hottest temperature occurred in the Plains, Midwest and Eastern Seaboard. Virginia had its hottest July on record, a full 4 degrees above average. Maryland’s July was 3rd hottest on record. In 32 of the 48 contiguous U.S. states, July ranked among the top 10 hottest. At least 35 cities/towns had their hottest day on record (any day of the year).

Precipitation as a percent of normal in July across the Lower 48 states (Regional Climate Center )

View Photo Gallery: The United States broke a 118-year heat record in July, and the world has been beset by extreme weather in recent weeks — floods, drought, typhoons, hurricanes and Arctic ice melt — raising concerns of scientists and policymakers. Here are examples of wild weather:

The worst of the drought centered in the Midwest and Plains. Nebraska, Iowa, Illinois, and Missouri had July precipitation totals ranking among their ten driest. NOAA said the area of the country in extreme to exceptional drought doubled from 10 percent in June to 22 percent in July. The drought reached the most extensive levels since December 1956.

View Photo Gallery: It has been more than a half-century since a drought this extensive hit the United States, NOAA reported July 16. The effects are growing and may cost the U.S. economy $50 billion.

The hot and dry conditions also stoked blazing wildfires, which consumed more than 2 million acres in July. That's a half a million acres above average, and the fourth most on record since 2000.

When considering connections to global warming and increasing concentrations of greenhouse gases, it’s important to recognize the area of the U.S. represents less than 4 percent of the globe and 2012 is just one year in a long history.

Having said that, global temperatures have also been running warm. While NOAA’s global report for July temperatures has not yet been issued, June ranked 4th warmest on record globally and marked the 328th consecutive month of above average temperatures.

As global temperatures have been elevated for some time and long-term averages are rising, it’s likely the same influences acting on global temperatures are also affecting temperatures on smaller scales.

In other words, increasing greenhouse gas concentrations are probably increasing the odds of these exceptionally warm years/months wherever one resides.